1. Field
This disclosure relates to an apparatus for driving a display panel, and more particularly, to an apparatus for driving a display panel capable of, in a case where a power source to be applied to a display panel is short-circuited due to a crack in the display panel, sensing the short circuit and turning off the power applied to the display panel from a DC-DC converter.
2. Description of the Related Art
With the development of semiconductor fabrication techniques and image processing techniques, commercialization and supply of flat panel displays which easily achieve reductions in weight and thickness and implement high image quality have rapidly advanced. As such flat panel display devices, there are liquid crystal displays (LCDs), plasma display panels (PDPs), vacuum fluorescent displays (VFDs), organic light-emitting diodes (OLEDs), and the like.
From among the flat panel display devices, LCDs and OLEDs have been widely employed in personal portable devices such as portable phones, PDAs, and portable computers due to their light weights, small thicknesses, and easy implementation of high image quality, and have been widely used particularly for external and internal windows of portable phones having dual windows.
Particularly, OLEDs are self-light-emitting and do not include backlights unlike LCDs, so that they are thinner, have faster response times of the order of tens of nanoseconds, have wide viewing angles and good contrast ratio, and thus are gaining attentions as the next-generation display.
As the display panels become thinner, there may be a case where cracks occur in the display panels due to external impacts. In this case, a short circuit occurs, and thus overcurrent flows through the display panel, resulting in increase in temperature and burn-out of the display panel. In addition, due to the short circuit, the DC-DC converter becomes overloaded, and thus the DC-DC converter itself or an inductor which is a peripheral component of the DC-DC converter may be damaged, affecting other nearby circuits.
As methods for solving the above-described problems, in the related art, only the mechanisms for protecting the DC-DC converter or the inductor exist, not the mechanism for protecting the panel itself.
Soft-start and thermal shutdown (TSD) functions are examples of the protective mechanisms of the DC-DC converters.
However, the TSD function is restored if the display panel temperature decreases due to hysteresis characteristics, and power is applied from the DC-DC converter to the display panel again. As a result, overcurrent flows through the display panel again and the temperature increases. Then, the power applied to the display panel from the DC-DC converter is turned off by the TSD function. Such operations are performed repeatedly. Moreover, in a case where a micro-short circuit (of about several milliamperes), not the complete short circuit, occurs in a drive region of the DC-DC converter, such functions cannot be operated.